The Belief in Miracles

The Rambam (Hilchos Yesodei HaTorah chapter 8) tells us that despite all the
great miracles that took place in Egypt, it still did not serve as positive proof that
Moshe was Hashem’s chosen prophet. That would be authenticated, positively
confirmed, and eternalized only at Mattan Torah – the Giving of the Torah – when all
the Jews; men, women and children , would see and hear for themselves as Hashem
spoke to Moshe.
That’s because even the greatest miracles are not irrefutable proof. It is possible for
miracles to be the work of magic or some other means of deception. Let’s remember
that even the Egyptian magicians were able to duplicate the first few plagues.